For the mechanical dividing of large pieces of meat into pieces, use is typically made of a so-called portion cutter. A portion cutter is a machine with a number of conveyor belts, a computer vision system, a knife and a control unit. Typically, there are two conveyor belts which are arranged end to end with a relatively small gap between them. The computer vision system can also be called a scanning system. The knife is typically of the “sword” type, i.e. a relatively long knife which is arranged at the side of the gap between the two conveyor belts. When a portion is to be cut from the piece of meat the meat is lying over the gap between the two conveyor belts, and the cut is carried out by the knife being rotated once at high speed, whereby the piece of meat is cut through.
FIG. 1 shows an example of a portion cutter indicated in general by the reference number 1. The items to be cut, for example pieces of meat 10, are transported on an inlet conveyor belt 2 forward to the machine where the piece of meat is first scanned 4, for example by means of laser vision equipment, X-ray equipment, ultrasonic equipment or similar measuring/scanning equipment. On the basis of this scanning, a number of pieces which fulfill certain criteria are determined, and a cutting-up 6 of the piece of meat 10 into portions and possibly trim pieces is carried out. As mentioned, this cutting-up is carried out for example with a rotating knife or the like. The portions may be transported away from the portion cutter in batches 12 by means of a conveyor 8.
The term “portion cutter” describes that the piece of meat is cut-up into portions, and the term “portion” is the term often used for the small pieces of meat. The machine can be used for the cutting of things other than meat, e.g. fish, poultry and cheese etc.
Since portion cutters were developed in the early 90's they have become faster and faster and more and more accurate. Today portion cutters have become more or less the industrial standard, high yield and capacity is obtained and focus is now set on easier handling of the “meat” both before the meat enters portioning cutters, and also after the meat has been processed into portions and trim. This way the integration of portion cutters into complete lines (systems) becomes easier.
As an example, when portioning a salmon filet into portions it is often desired to make a little “trim” in the neck end and at the “tail” end. The reason is that the portions then will appear more uniform. In this case the salmon fillet will be divided into two different products: the “portions” and the “trim”. It is clear that it would be desirable to separate these two products in two flows for easier packing etc. Today this is done either manually or by some kind of a mechanical separation. The mechanical separation today is done after the actual portion cutters. Mechanical separator can as an example be rejections arms, drop conveyors, air nozzles etc.
The problem is that especially small trim (desired because of the high yield) tends to move in the cutting process and therefore it can be very difficult to separate it from the portions by a mechanical separator since the trim can move very close to a portion. Another problem is that before separating the trim from the portions in two flows it needs to be pre-separated lengthwise in the portion cutters. This is often done by letting the outlet belt run faster than the inlet belt. The disadvantage by doing this is that either the capacity suffers or the accuracy will suffer since the salmon fillet is stretched because it is supported by to belts with different speed. Another possibility is to have a mechanical device to make this separation but that would add cost and require more floor space.
The inventor of the present invention has appreciated that there is thus a need for an apparatus where the handling of the portions and trim is simplified and that has a higher capacity and has in consequence devised the present invention.